The large copper butterfly Lycaena dispar (Haworth, 1803; Lepidoptera: Lycaenidae) has been categorized as a near-threatened species (NT) in South Korea from 2012 mainly due to limited distribution. In this study, we visited 36 sites spread across all South Korean provinces to verify the distributional range of the species and sequenced mitochondrial COI for 53 individuals from nine sites. We observed L. dispar at 15 sites in six provinces, including the two previously known provinces, indicating a southward range expansion. The in-field monitoring and genetic data collectively suggested that L. dispar does not have a limited distribution nor is it isolated, indicating that it should be reclassified as less vulnerable. Our study demonstrates that the combination of field and genetic data can provide a more reliable assessment of the stability of a species.

• Jeong Sun Park(Department of Applied Biology, Chonnam National University, Republic of Korea)
• Seung Hyun Lee(Department of Applied Biology, Chonnam National University, Republic of Korea)
• Jee-Young Pyo(Department of Applied Biology, Chonnam National University, Republic of Korea)
• Heon Cheon Jeong(Korea Native Animal Resources Utilization Convergence Research Institute, Soonchunhyang University, Republic of Korea)
• Sung-Soo Kim(Research Institute for East Asian Environment and Biology, Seoul, Republic of Korea)
• Iksoo Kim(Department of Applied Biology, Chonnam National University, Republic of Korea) Corresponding author